Conversion of model sulfur compounds to characterize hydrodesulfurization CoMo/Al2O3 catalysts

Leglise, J.; Finot, Laurent; Gestel, J.N.M. van; Duchet, J.C.

doi:10.1016/s0167-2991(99)80393-0

Cited by 20 publications

(5 citation statements)

References 30 publications

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“…The promoters (such as cobalt and nickel) decorate MoS 2 crystals at the edge sites of the slabs. The H 2 S/H 2 ratio and their heterolytic dissociation , are critical parameters for maintaining the optimal number of CUS. The presence of −SH groups that possess a Brønsted acid character has been confirmed. ,, Apparently, hydrogen activation, which is required for hydroprocessing reactions, occurs on CUS.…”

Section: Catalyst Materials and Its Characterizationmentioning

confidence: 99%

On the Use of Acid-Base-Supported Catalysts for Hydroprocessing of Heavy Petroleum

Leyva

Rana

Trejo

et al. 2007

Ind. Eng. Chem. Res.

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The environmental regulation pressure is being increased to reduce precursors of pollution contaminants (sulfur, nitrogen, and aromatics) in fuels to lower levels. There are various processes to upgrade heavy and extraheavy crude oils, such as solvent deasphalting, thermal conversion, catalytic conversion, distillation, and hydroprocessing. Hydroprocessing not only upgrades the crude oil but also produces synthetic crude oil that has a lower impurities content and a higher liquid yield of products. The fuels upgrading currently is achieved in refinery hydroprocessing units using different new-generation catalysts, along with several modifications of process conditions such as multistage reactors, type of catalyst loading, and reactor internals. However, it has been widely recognized that, for deep removal of these contaminants by hydroprocessing, research must be more oriented to the catalyst developments, rather than the process conditions. Actual commercial catalysts are based on well-known and studied active metals (CoMo, NiMo) and support (Al 2 O 3 ). In addition, extensive research work has been performed with other supports (Al 2 O 3 -TiO 2 , Al 2 O 3 -ZrO 2 , etc.). Nevertheless, other promising acidic materials, such as zeolites, have received relatively less attention, and experimental reports on their use as part of the heavy oil hydroprocessing catalyst support are scarce in the literature. The objective of this contribution is then to discuss the use of acidic and/or basic materials as a support for the hydroprocessing catalyst, specifically for their possible application for the hydroprocessing of heavy oils, in cases where the desired product selectivity is toward gasoline and middle distillates.

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Section: Catalyst Materials and Its Characterizationmentioning

confidence: 99%

On the Use of Acid-Base-Supported Catalysts for Hydroprocessing of Heavy Petroleum

Leyva

Rana

Trejo

et al. 2007

Ind. Eng. Chem. Res.

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“…It is often used to perform a rapid evaluation of the catalytic performance of a new catalytic formulation, although the effectiveness of such a screening is under debate. 17 In recent years, with the fast development of computer, more complicated S-contained compounds were used as model catalysts to investigate the HDS mechanism by numerical calculations. However, the investigation of thiophene HDS mechanism is able to capture the key features of the catalytic performance which can provide references for understanding HDS of other thiophene-derived species.…”

Section: Introductionmentioning

confidence: 99%

“…The simplest homologue of the family of sulfur-containing molecules, which are refractory to classical HDS, is thiophene. It is often used to perform a rapid evaluation of the catalytic performance of a new catalytic formulation, although the effectiveness of such a screening is under debate . In recent years, with the fast development of computer, more complicated S-contained compounds were used as model catalysts to investigate the HDS mechanism by numerical calculations.…”

Section: Introductionmentioning

confidence: 99%

Density Functional Theory Investigation on Thiophene Hydrodesulfurization Mechanism Catalyzed by ReS₂ (001) Surface

et al. 2016

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We present density functional theory calculations on the reaction mechanism of thiophene hydrodesulfurization (HDS) over ReS2 (001) surface under typical HDS reaction conditions. It is found that thiophene adopts an “upright” adsorption configuration with the binding energy of 1.26 eV. Considering the factors such as Bader charge, two reaction mechanisms, named direct desulfurization (DDS) to the product of butadiene and hydrogenation (HYD) to 2-butene, 1-butene, and butane, are systematically investigated. Results show that H prefers to attack thiophenic C before the first C–S bond rupture but begins to hydrogenate ST (S atom of thiophene) after ring-opening. Prehydrogenation has different effect on the activity of C–S bond breaking. When the ring is intact, it has nominal effect; but when the ring is open, appropriate prehydrogenation can dramatically decrease the energy barrier while complete hydrogenation makes the barrier rise again due to stereohindrance effect. The DDS mechanism is proved to be kinetically unfavorable while 2-butene is suggested to be a predominated product for HYD mechanism. The role of Sa (preadsorbed S) is a “ladder” which helps H approach the thiophenic molecule while ST acts as an “intermediary” for H exchange. Changing reaction conditions through partial pressure of H2 can only alter the rate-determining step but has nothing to do with the catalytic selectivity.

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“…Nickel-and cobalt-promoted molybdena-alumina catalysts are used extensively in hydrotreatment technologies for the deep hydrodesulfurization of the significant amounts of sulfurorganic compounds in petroleum fractions [1][2][3][4][5]. _________________________ * Corresponding author.…”

Section: Introductionmentioning

confidence: 99%

On the surface coverage of alumina by molybdenum-oxide in nickel - and cobalt-promoted MoOx/Al2O3 catalysts

Matusek

Schay

Tétényi

2008

React Kinet Catal Lett

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The chemisorption of CO 2 has been studied on alumina-supported Co-and Nipromoted molybdenum-oxide (CoMo, NiMo) and, besides those, on monometallic Co and Ni. Chemisorbed amounts on the monometallic samples were equal to that on the alumina support. XPS measurements were performed with the NiMo and Ni samples. The amounts of surface Mo-and Al-ions were calculated. It could be established that molybdenum oxide forms a near to monomolecular layer on the Co-and Ni-promoted molybdena-alumina samples.

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Conversion of model sulfur compounds to characterize hydrodesulfurization CoMo/Al2O3 catalysts

Cited by 20 publications

References 30 publications

On the Use of Acid-Base-Supported Catalysts for Hydroprocessing of Heavy Petroleum

On the Use of Acid-Base-Supported Catalysts for Hydroprocessing of Heavy Petroleum

Density Functional Theory Investigation on Thiophene Hydrodesulfurization Mechanism Catalyzed by ReS₂ (001) Surface

On the surface coverage of alumina by molybdenum-oxide in nickel - and cobalt-promoted MoOx/Al2O3 catalysts

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Conversion of model sulfur compounds to characterize hydrodesulfurization CoMo/Al2O3 catalysts

Cited by 20 publications

References 30 publications

On the Use of Acid-Base-Supported Catalysts for Hydroprocessing of Heavy Petroleum

On the Use of Acid-Base-Supported Catalysts for Hydroprocessing of Heavy Petroleum

Density Functional Theory Investigation on Thiophene Hydrodesulfurization Mechanism Catalyzed by ReS2 (001) Surface

On the surface coverage of alumina by molybdenum-oxide in nickel - and cobalt-promoted MoOx/Al2O3 catalysts

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Density Functional Theory Investigation on Thiophene Hydrodesulfurization Mechanism Catalyzed by ReS₂ (001) Surface